如何计算午夜时列中的值之间的时间差？

Question

I have a column of timestamp values for each hour for 25 days. I want to take the time difference between them. I have tried the code in the past but it gives me a negative value. I have this new code, but it is for two values, but how can I tweak it to loop over the values of column?

def time_diff(start, end):
    if isinstance(start, datetime_time): # convert to datetime
        assert isinstance(end, datetime_time)
        start, end = [datetime.combine(datetime.min, t) for t in [start, end]]
    if start <= end: # e.g., 10:33:26-11:15:49
        return end - start
    else: # end < start e.g., 23:55:00-00:25:00
        end += timedelta(1) # +day
        assert end > start
        return end - start

Answer 1

Use:

s = dataFrame.groupby(['DeviceName'])['Time_ist_td'].diff()
dataFrame['Time_diff']=s.where(s>pd.Timedelta(0),-s).dt.total_seconds()) // 60

---

basic idea:

s=pd.Series([-1,1])
print(s)

0   -1
1    1
dtype: int64
s=s.where(s>0,-s)
print(s)

0    1
1    1
dtype: int64